This invention relates to brake linkages which extend between vehicle brakes and operator controls such as foot pedals or hand levers.
Conventional vehicles typically provide a single brake which is linked to a single brake control. A parking brake is often provided for locking the control or a portion of the linkage in an engaged mode.
It is known to provide right and left respective brakes which can be used for steering the vehicle. Typically each side brake has an independent linkage to a pedal or control which is independently operable to steer the vehicle by braking one side. A latch is often provided for coupling the pedals together to thereby cause both brakes to be applied together. However, inaccuracies in the lengths of the independent linkages, and wear in the various parts and brakes can cause the brakes to be applied at different rates such that the vehicle still executes at least a slight turn. These conventional mechanisms typically do not equalize the forces applied to the respective brakes.
Another type of brake mechanism provides right and left brakes which are each independently coupled via tension cables or rods to the lateral ends of a horizontal shaft. As the shaft is pulled, both tension cables are pulled, thereby applying both brakes. When the operator engages the brake control, the shaft is pulled and will also pivot slightly about a vertical axis to take up any slack or difference in length of the left and right tension cables. The pivotal motion of the shaft about the vertical axis thereby first compensates for linkage slack or length differences, and then applies the left and right brakes generally equally. When one of the linkages extending between one of the vehicle brakes and the shaft becomes disengaged, the shaft can pivot excessively about its vertical axis when the control is engaged, and the other side brake may thereby be rendered inoperative.
It would be desirable to provide a brake mechanism which equalizes the brake force applied to right and left vehicle brakes, and which is adjustable to compensate for manufacturing inaccuracies or wear over time. It would also be desirable to provide a brake mechanism which is engagable by either a hand lever or a foot pedal. It would be desirable for such a hand lever to be operative to engage a parking brake feature, and for the foot pedal to be operatively engagable to assist the operator in applying the parking brake. It would further be desirable for such a mechanism to allow the portion of the linkage which extends to one side brake to remain operative if and when the linkage to the other side brake becomes disengaged and inoperative.